Endurance enhancement related to the human angiotensin I-converting enzyme I-D polymorphism is not due to differences in the cardiorespiratory response to training

Abstract.

Human physical performance is strongly influenced by genetic factors. We have previously reported that the I variant of the human angiotensin I-converting enzyme (ACE) gene is associated with greater endurance performance in mountaineers and Olympic runners and improved performance in army recruits. In this study we examined whether this effect is mediated by improvements in cardiovascular fitness with training in 58 army recruits homozygous for the insertion (I, ACE genotype II) or deletion (D, ACE genotype DD) allele. A submaximal and maximal exercise protocol was used to calculate both the heart rate/oxygen uptake ($\dot V{\rm O}_{\rm 2}$ ) relationship and changes in maximal oxygen uptake ($\dot V{\rm O}_{{\rm 2max}}$ ), respectively. There was no significant intergroup difference in $\dot V{\rm O}_{{\rm 2max}}$ at baseline (P=0.19) or after training (P=0.22). There was no difference between genotypes with training in the heart rate/$\dot V{\rm O}_{\rm 2}$ elevation (P=0.79 for the mean difference in mean adjusted heart rates). However, $\dot V{\rm O}_{\rm 2}$ at all exercise intensities in the submaximal test was lower for all subjects after training and at 80 W the reduction in $\dot V{\rm O}_{\rm 2}$ was greater for the II subjects compared to DD subjects [mean(SEM)] [1.6  (0.27) and 0.68 (0.27) ml kg^–1 min^–1, respectively; P=0.02 for mean difference]. The I/D polymorphism may play a role in enhanced endurance performance but this is not mediated by differences in $\dot V{\rm O}_{{\rm 2max}}$ or the heart rate/$\dot V{\rm O}_{\rm 2}$ relationship in response to training.